The present invention relates to a method and a machine for the vaccination of fishes, especially trout and salmon fry.
Today, vaccination of fishes takes place either by hand or by placing the fishes in a bath containing a vaccine.
Manual vaccination of fishes is very time-consuming and consequently very expensive. At the same time, a vaccination capacity is too low in relation to a need therefor. By means of manual vaccination only a small part of the fish fry can thus be vaccinated each year, considering the extent to which breeding takes place today.
"Bathing" the fishes in vaccine-containing water represents a rapid and expensive method. In practice it has been found that it is not particularly efficient in that only about 60% of fishes become thereby vaccinated.
U.S. Pat. No. 3,229,326 relates to an arrangement for feeding fishes from a vessel containing water to a machine for non-specified fish treatment. The method and machine taught by this prior patent specification exhibit features which advantageously may be utilized in the vaccination of fishes. In U.S. Pat. No. 3,229,326 a method for treatment of fishes is disclosed wherein fishes, which are in a vessel containing water, are conveyed upwardly by a conveyor and carried onto a unidirectional device which ensures that the fishes are fed head first in a feeding direction by means of an edgewise-turner which turns the fishes edgewise to a fish treatment machine. The machine disclosed in U.S. Pat. No. 3,229,326 comprises a vessel containing water, a conveyor extending downwardly into the vessel for conveying fish upwardly from the vessel. The conveyor delivers fishes to an unidirectional device having self-feeding motion (reciprocal motion, vibratory motion) in a feeding direction of the fishes. The unidirectional device ensures that the fishes are fed head first in the feeding direction to the edgewise-turner coupled after the unidirectional device wherein the unidirectional device, having self-feeding motion (reciprocal motion, vibration), comprises longitudinal chutes which, in combination with its self-feeding motion, turn the fishes, so that the fishes, lying edgewise, arrive at the fish treatment machine.
It is a purpose of the present invention to eliminate disadvantages of previous vaccination methods and to provide an efficient method which allows for rapid and lenient (non-injurious) vaccination of each individual fish. It is a further purpose of this invention to provide a machine for carrying out this method which is reliable, of high capacity and capable of ensuring precision vaccinations of the fishes.